The world's fastest-growing religion is ...

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Islam, the world's fastest-growing faith, will leap from 1.6 billion to 2.76 billion by 2050, according to the Pew study

Study collected data from 234 countries and territories; predicts fate of five major faiths -- Buddhism, Christianity, Hinduism, Judaism and Islam -- as well as folk religions and atheists

If tech futurists are to be believed, by the year 2050, robots will do many of our errands and drive our cars. If a new study on religious trends is to be believed, many of those robot-controlled cars will stop and park at mosques and churches.

Yes, despite predictions that religion will go the way of dinosaurs, the size of almost every major faith -- sorry, Buddhists -- will increase in the next 40 years, according to a study released Thursday by the Pew Research Center.

The biggest winners, Pew predicts, will be Islam and Christianity.

Muslims form 'Ring of peace' at Oslo synagogue 4 photos

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Muslims form 'Ring of peace' at Oslo synagogue 4 photos

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Muslims form 'Ring of peace' at Oslo synagogue 4 photos

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Muslims form 'Ring of peace' at Oslo synagogue 4 photos

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Muslims form 'Ring of peace' at Oslo synagogue 4 photos

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Muslims form 'Ring of peace' at Oslo synagogue 4 photos

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Muslims form 'Ring of peace' at Oslo synagogue 4 photos

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Muslims form 'Ring of peace' at Oslo synagogue 4 photos

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Islam, the world's fastest-growing faith, will leap from 1.6 billion (in 2010) to 2.76 billion by 2050, according to the Pew study. At that time, Muslims will make up nearly one-third of the world's total projected population of about 9 billion people.

Christianity is expected to grow, too, but not at Islam's explosive rate. The Pew study predicts Christians will increase from 2.17 billion to 2.92 billion, composing more than 31% of the world's population.

This means that by 2050, more than 6 out of 10 people on Earth will be Christian or Muslim. And, for perhaps the first time in history, Islam and Christianity would boast roughly equal numbers.

Looking even farther into the future, Islam's population could pass Christianity by 2070, Pew says, despite Christians' six-century head start. (It's possible that Muslims outnumbered Christians some time in the past, perhaps during the Black Plague that decimated Europe. But scholars aren't certain.)

Based in Washington, Pew is a nonpartisan "fact tank" that regularly produces sweeping surveys of this kind without taking public policy positions. Six years in the making, its study collected data from 234 countries and territories to predict the fate of five major faiths -- Buddhism, Christianity, Hinduism, Judaism and Islam -- as well as folk religions and the religiously unaffiliated, including atheists.

The study, which Pew says is the first of its kind, bases its projections on the age of populations, fertility and mortality rates, as well as migration and conversion patterns. Simply put, Muslims are having larger families, retaining more members (conversions are illegal in some Muslim nations) and are younger than adherents of other faiths. More than 1 in 3 Muslims is younger than 15. But religious trends have never been measured on the study's vast scale, Pew says, so a few cautions are in order.

First, the population projections are based on current data and assumptions about demographic trends. For example, Muslim women have an average of three children, the highest of any religious group. In the future, if education and employment rates rise, those numbers could change.

Second, nobody at Pew has a crystal ball, so events like cataclysmic wars, rampaging diseases, natural disasters and economic meltdowns could throw the numbers off.

But it's clear from the 245-page report that Pew and the demographic experts they consulted did their homework, so the study is worth taking seriously. With that in mind, he